What should we pay attention to?

Are you planning to invest in photovoltaics, but you’re not sure which offer to choose? Do you want your installation to be safe and efficient, while also aiming for the lowest possible price? Photovoltaics must be of high quality – otherwise, it won’t be cost-effective or safe. The Luxembourg is characterized by very high levels of sunshine, which is why we have so many orchards and agriculture here. Favorable weather, fertile soil, and abundant sunshine are very good conditions for agriculture, but also for photovoltaic installations. The more sunlight, the faster the return on investment. Before you decide to install photovoltaics, get to know the most common mistakes related to the selection and installation of photovoltaic panels.

Most common mistakes in photovoltaic installations

Photovoltaics in Luxembourg are becoming increasingly popular. There are more and more micro-installations of photovoltaics, which may seem like an ideal situation, but in reality, many systems are poorly executed, and the responsibility for this lies primarily with the “professionals” in the photovoltaic industry, but also partly with the customers seeking excessive savings. So, how can you avoid costly mistakes?

Below, we present the most common mistakes in photovoltaic installations in Luxembourg, which may occur during the design and installation of selected solutions.

1. Shaded installation location

It is worth knowing that photovoltaics in the city of Luxembourg and surrounding suburban areas are very cost-effective due to the high sunshine levels in our region, and we should wisely use the possibilities provided by the location.

The placement of photovoltaic panels should enable maximum utilization of solar energy. Therefore, the photovoltaic installation is mounted on the southern sides of roofs or on ground structures facing south, where the panels can “collect” the most sunlight and produce more energy. There is no point in installing photovoltaics in poorly sunlit areas, as such an installation will not be efficient and will extend the payback period – reducing the quality and efficiency of the installation overall.

The most common mistakes concern the wrong choice of installation location. Avoid mounting on:

• roofs shaded by other buildings or trees
• cells can also be shaded by other PV installation elements or building parts, e.g., facades or bay windows.

Remember that shading just 3% of the PV panel’s surface can reduce the efficiency of the photovoltaic installation by up to 25%. However, there is a solution to this issue – choose the appropriate technology that uses power optimizers. This is the only way to effectively combat shading, says an expert from VOLTMAX, a Luxembourg-based company specializing in photovoltaic installations for businesses, individual customers, and agricultural farms.

2. Choosing a company that uses subcontractors

Choosing a contractor for a PV installation is one of the key issues. The company hired for this task must have experience and a team of qualified employees who constantly improve their skills.

Using an offer from an unknown and untested company may lead to problems later on and could me a mistakes with photovoltaic installation. When assessing the reliability of a contracting company, consider the installation cost estimate and the specification of used components and materials. If the proposed price is lower than the average market prices, there is a suspicion that the company will send subcontractors for the installation, who may not be familiar with the chosen solutions and install them improperly. Another problem is the lack of client awareness among the proposed technological solutions and components. Many representatives may offer components of very poor quality at an inflated price, while praising them. Therefore, the lack of curiosity and involvement of the client in the investment can cause many problems, and as life shows, cost-cutting can be detrimental and lead to long-term costs.

3. Lack of lightning protection system

A good practice to protect against storms and surge consequences is the installation of lightning protection devices. The need to place them on the roof is considered individually during a meeting with the photovoltaic company’s expert, whose services we decide to use.

Although such situations are very rare, they cannot be excluded. Panels should also be well placed in relation to the lightning protection elements – they must be located in a protected space but with the appropriate insulation gap.

4. Loose screws

Improper tightening of screws can lead to panels detaching from the roof surface or ground structure and damaging the system.

Any haste in installing photovoltaic installations is very deceptive – even a small oversight can have tragic consequences and cause not only financial losses but also endanger health or life.

Expert VOLTMAX – “From experience, we know situations where errors in photovoltaic installations in Luxembourg due to loose screws could result in a fire because the dislodgement of the screw leads to the failure of originally supported elements, which is not their purpose.”

5. Incorrectly laid photovoltaic cables

Incorrect cable laying can cause them to wear out; cables laid in a way that rub against each other or other elements can lead to unnecessary malfunctions.

Poorly laid cables can also be exposed to moisture, resulting in a short circuit. The quality of the cables themselves is also very important – the installation must last for many years (25-30 years), and for this to be possible, all even the smallest elements must meet specific requirements. The quality of the cabling used also affects the effectiveness of the generated power, which we will use or pass on to the grid.

6. Incorrectly connected photovoltaic panels

Next common mistakes is that incorrectly connected photovoltaic panels can result in incorrect operation of the photovoltaic installation or its failure, and in extreme cases, even a fire.

How does it look in VOLTMAX?

Expert VOLTMAX: “You must remember that a condition for the warranty of photovoltaic installations is the correct installation method. So, if the cells are connected incorrectly and get damaged, the complaint may not be accepted. For proper connections, high-quality cables and connectors must be used – relying on cheap substitutes of questionable origin is the shortest path to problems that can be avoided by opting for optimal quality and cost solutions.”

7. Improper tilt angle of panels

The tilt angle of photovoltaic panels should be chosen according to the specifics of the location where they will be installed. Panels used in photovoltaic installations can be mounted on both steep and flat roofs. In the latter case, a special structure is necessary to lift the cells and enable their proper positioning relative to the incident light.

If the panels have too small or too large a tilt angle, they will not properly utilize solar energy. The greatest power efficiency will be achieved by mounting panels at an angle of 25-36 degrees.

8. Incorrectly chosen design of the photovoltaic installation

Specialists involved in the creation of the installation design must consider the dimensions and load capacity of the roof, as well as the arrangement of individual installation elements in such a way that the installation is made according to the art and complies with all standards of proper installation while also fitting nicely into the appearance of our building, as the installation should please not only our wallet but also our eyes. A poorly executed project may result in the need for subsequent modifications, which will entail additional costs and delays.

The photovoltaic installation design for a building should be carried out by a person who has construction qualifications for designing electrical and electro-energy devices or a certificate in the field of photovoltaic systems issued by the President of the Office of Technical Inspection.

The installation elements should meet certain technical requirements:

• Photovoltaic modules must have efficiency levels of not less than 16%, silicon cells, and mechanical strength of not less than 5,400 Pa.
• The inverter should have a transformerless design, be characterized by at least IP65 protection class, and be equipped with convection or fan cooling.

Particularly important is the proper power rating of the installation; too low power will not allow covering the energy demand, and deficiencies will have to be supplemented from the grid, which will result in additional costs and reduced PV installation profitability. Too much power is also a mistake as it will cause unnecessary financial losses associated with the purchase of “stronger” solutions completely unsuited to our needs.

A flawless photovoltaic installation – it’s possible

Can we avoid problems with structural defects in photovoltaic installations? Expert VOLTMAX: “Of course, yes, you just need to meet the following points:” Now you know what is common mistakes in photovoltaic instalations.

• The condition is to choose a reliable supplier.
• Appropriately assess your needs, capabilities, and risks associated with owning a photovoltaic installation in the Luxembourg with our expert.
• At home, when considering a photovoltaic installation contractor, I encourage you to make a appoitment with our expert: +352 691 986 312
• Check the subsidies and financial aid programmes

Customers opting for photovoltaics should also consider its insurance – the cost of such a policy is not high, and insurance will cover potential costs not included in standard building insurance.